Shoulder problems typically are indicative of poor technique rather than strings, but if you're looking for a more comfortable ride, you can always hybrid the alu with a soft synthetic gut if you want to maintain a budget, i suggest Forten Sweet (synthetic gut), or Ektelon Power Play (i.e. prince syn gut soft).
If you want to just improve the feel without too much of a budget in mind, you can hybrid it with a gut in the crosses or mains. The gut in the mains will play very differently, but will still give you a decent amount of control with the alu in the cross. With the ALU in the mains, you'll get a more cushioned ride.